Edmund a



(No Model.)

E. A. PARKER. Student-Lamp.

No. 231,353. Patented Aug. 17,1880. Y

mi Mmm UNITED STATES PATENT OEEIcE.

EDMUND' A. PARKER, OF WEST MERIDEN, CONNECTICUT, ASSIGNOR TO BRADLEY & HUBBARD MANUFACTURING COMPANY, OF SAME PLACE.

STUDENT-LAM P.

SPECIFICATION forming part of Letters Patent No. 231,353, dated August 1*?, 1880.

Application filed April 12, 1880. '(No model.)

To all 'whom it 'may concern:

Be it known that I, EDMUND A. PARKER, of West Meriden, in the county of New Haven and State of Connecticut, have invented a new Improvement in Student-Lamps; and I do hereby declare the following, when taken in connection with the accompanying drawings and the letters of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawings constitute part of this specification, and represent, in

Figure l, a side view; Fig. 2, au enlarged sectional side view at right angles to Fig. 1; Fig. 3, a longitudinal section; Fig. 4, a transverse section of a. modification.

This invention relates to animprovementin that class of lamps well known as German study-lamps-that is, a lamp in which the fount and burner are arranged to be adjustable on a vertical rod. In the usual construction the adjustment is effected by means of a set-screw through the socket ou the rod, so that by turning it hard against the rod the lamp will be fixed in that position, or, loosening the screw, may be adjustable to diii'erent elevations and reset.

A serious ditiiculty is experienced with this class of lamps because of the liability of the lamp to slip down the rod of its own weight. This frequently occurs because of not properly setting the screw or by its accidental loosening.

The object of this invention is to avoid this difficulty; and it consists of the automatic setting device hereinafter described, and particularly recited in the claim.

A represents the vertical supporting-rod upon which the socket B slides, and to which socket the fomit CY is attached, as also the burner, in the usual manner.

D is a set-screw, tapped through the socket so as to bear directly or indirectly' against the rod in the usual manner.

E is the head by which the set-screw is conveniently turned. In connection with the screw is a spring, here represented as a spiral spring, F, onelend, a,'of which is in connection with the socket, the other, d, in connection with the screw, the tendency of the spring being to turn the screw inward, and it is of 5o sufficient strength to produce the required friction to positively set and hold the socket,

as seen in Figs. 3 and 4, to the rod, and so that if the screw be turned to release the socket to permit it to be raised or lowered the screw must be held in the loosened position until the desired movement of the socket on the rod is complete. Then, when the screw is released it is automatically turned by the spring into its set condition. Hence, if the 6o screw be not held as above described while the socket is being moved, it will set and hold the socket so that it cannotbe moved, and all possible accidental movement of the socket is avoided. 6

While representing the spring as that of a spiral character, other springs may be usedas, for instance, the head E of the screw may be a hollow cylinder, or what is commonly called a barrel, with a coil-spring, F', with- 7o in it, the outer end of which is attached to the inner circumference of the barrel E and the other to the socket B, which is extended within the head, as seen in Fig. 3, the screw D passing through the socket to bear on the rod, as in the first instance. This arrangement conceals the sprin'.

Other arrangement of the spring may be employed, the last illustration being suflicient to enable others skilled in the art to apply the 8o spring to the screw and socket.

This invention may be applied to that class of lamps which are suspended by a rod from the ceiling, and so as to be adjustable on the rod. I therefore do not wish to be understood as confining this invention to table-lamps.

I claim- The herein-described improvement in adjustable lamps, consisting of the supportingrod and socket thereon, combined with a set- 9o screw and spring, one end of which is attached to the socket and the other to the screw, and operating to automatically set the screw, substantially as described.

EDMUND A. PARKER.

Witnesses:

GEORGE A. FAY, FRANK S. FAY. 

